bouchet



No. 623,5H. v Patented Apr. 25, |899. M. BOUCHET.

AUTOMATIC ELECTRIC CIRCUIT BREAKEB.

. y(.Apqnlicatioxz led Jan. 31, 1898.)

2 Sheets-Sheet I.

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(N0 Model.)

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Patented Apr. 25, |899.

M. BOUCHET.

AUTOMATIC ELECTRIC CIRCUIT BREAKER.

(Applicz FJE 4 ign led Jan. 31, 1898.)

2 Sheets Shee 2.

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Z VIII/150! UNITED STATES- PATENT OFFICE..v

MAURICE BOUCHET, OF PARIS, FRANCE.

AUTOMATIC ELECTRIC-CIRCUIT BREAKER.

SPECIFICATION forming part of Letters Patent No. 623,511, dated April. 25, 1899.

Application filed January 31,1898. Serial No. 668,579. (No model.)

To alli/071.0711, t may concern:

Be it known that I, MAURICE BoUcHnr, engineer, of 22 Rue Alphonse de Neuville, in the city of Paris, France, have invented an Improvement in Automatic Electric-Circuit Breakers, (for which l have iiled patent applications in France on the 2d of July, 1897, under No. 268,392; in `Belgium on the 2d of July, 1897, No. 120,221, and in Germany on the 23d of July, 1897,) of which the followingis a full, clear, and exact description.

My invention relates to apparatus for au tomatically breaking an electric circuit when the current exceeds a certain intensity and at other desired times.

My improved circuit-breaker can either be operated by hand or from a distance and may also be employed as a switch.

My invention consists, essentially, of a receptacle having` cavities separated byan insulating-partition and each containing mercury whose level is below the upper edge of the partition, so that, irst, a rise in the level of the mercury above the partition will establish electric communication between the cavities, and consequently between the conductors leading thereinto; second, when the mercury is allowed to fall to its normal level below the top of the partition the breaking of the circuit is produced in the mercury itselfgvhile the interposition of the partition prevents the formation of any arc.

Reference is to be had to the accompanying drawings, forming part of this specification and showing a preferred form of apparatus embodying my invention, whereinM Figure 1 represents a vertical section of the apparatus, the circuit being closed. Fig. 2 is a transverse vertical section on line 1 2, Fig. 1. Fig. 3 is a horizontal section on line 3 4 of FiO. 2. Fig. 4 is a vertical section of the apparatus, the circuit being open or broken. Figs. 5 and 5L represent a modification of my device, Fig. 5 being a vertical section and Fig. 5L being a horizontal section on line 5 5L of Fig. 5. Fig. 6 is a vertical section of a modification designed for use with currents of high tension wherein two partitions are employed to divide a possible arc. Fig. 7 shows the apparatus applied as a bipolar-circuit breaker. Fig. S represents the apparatus as provided with a safety device, hereinafter described;

and Fig. 9 is a horizontal section on line 5 (3, Fig. 8.

`The improved circuit-breaker shown herein consists, essentially, of a containerA, of orcelaiu or other insulating material, provide with two or more cavities a l), separated by a partition c and containing mercury up to the level n, Fig. 4, below the top of partition c or below an orifice made in said partition. Each cup a b is in communication with one of the poles of the circuit, and all passage ofthe current is prevented by the partition c when the mercury is at its normal level. The rise of the mercury above the top of the partition or above the lower edge of the orifice therein is produced by the action of displacing-plungers dipped into the cups a Z).

The apparatus is provided with a block B of insulating material, forming a pairof plungers of suitable form, disposed above the cavi ties a h and capable of being lowered into the same, so as to raise the level of the mercury to the level fn', Fig. 1, above the top edge of the partition o, so as to establish electrical communication between the two chambers a b. (See Figs. 1 and 2.) On raising plunger B the mercury returns to its original level n, as shown in Fig. 4, and the breaking of the circuit is produced in the liquid itself without lowering any contact-piece, and, further, the formation of an are is prevented owing to the interposition of the insulating-partition be tween the two poles of the circuit.

The plunger B is attached to the core d of an elec-tromagnet supported on the mercury container A by means of screws having insulated heads, a washer r, of elastic insulating material, being interposed between said core and the plunger B. When the circuit is closed, the current passes from one cup to the other and traverses the electromagnet, and when the current exceeds the limit desired the electromagnet raises the plungers, thereby causing the mercurydevel to be lowered, and the two cavities a h are no longer in communication and the current becomes interrupted.

The electromagnet may be of any type; but preferably l employ a special arrangement of electromagnet composed of three parts of magnetic material--viz., a part D forming one cheek of the bobbin and provided with a polar tubular extension-piece which while serv IOO ing for the passage of the lines of force considerably diminishes the reluctance of the airgap, a part E, forming the other cheek of the bobbin and provided with a polar extension e of decreasing section, and a sheath C, uniting the parts D and E.

Vhen the circuit is closed and the intensity of the current is below that of the direct self-induced or extra current, the core occupies the position represented in Figs. l and 2, the reluctance of the air-gap being relatively feeble and that of parts D and E but triiiing. The action of the ampere-turns developed in the coil is directed upon e, where the effect is then very powerful. Themagnetic flux tends to cause a forward progression or thrust of the core for increasing` the section of passage of the lines of force. The force exerted between two points of mevemen t of the core will depend upon the increased section ol'tered to the flux between these two points. Thus by adapting a suitable shape for the extremity e ef part E the force acting on the core may be rendered constant. The core d is surmou nted by a non-magnetic metal rod (Z, sliding freely in the head E, and is also guided by a disk or washer R, placed beneath the head D. This disk or washer, which is made of insulating` material, protects the electromagnet from all contact ot' the mercury and forms a tight joint with the top of vessel A.

M is a cap or cover for the apparatus, provided with a finger-piece, and which may be pivoted at .l in bearings S, screwed to the sheath C. The cover M is jointed tothe rod d, so as to partake of the movements ot' the core (Z and plunger l.

P is a spring jointed at the one end to the pin J' on bearing S and at its opposite end to cover M and serving to hold the cover down when the core is in the position corresponding tc closed circuit (see Fig. l) and to raise the covercntirely off when the electromagnet commences to act, (see Fig. 4,) the cover being forced by the spring to pass suddenly from one position to the other, which movement is effected by placing the pin G of the spring below aline drawn through .l J. The inclination of the cover M, and consequently the position of axis G relatively te the line J J', is regulated by an adjusting-screw (seen clearly in Fig. l) for enabling the sensitiveness of the apparatus to be modified. This sensitiveness of the apparatus may also be obtained with the aid et counterweights balancing the action of the electroinagnet. In this case the spring simply serves to continue the movement commenced bythe electromagnet and hold the cover M raised.

The current arrives by the terminalf, Figs. 2 and 3, which is electrically connected to the mercury-cup a by screw g. The other cup Z) is connected tothe electromagnet-coil by the wire h. The opposite end of the bobbin is connected to the terminal t by the wire Supposing the apparatus to be in the posi.- iion shown in Fig. t, by pressing on cover M the core CZ and plunger D are caused to descend and the two members of the latter to dip intothe cups a l) of the mercury-container, whereupon the level of the mercury will rise above the separating-partition e and the cups aand h will be put in electrical communication and the circuit closed. Should the intensity of the current exceed the desired limit, the force exerted upon the core d overcomes the resistance oi' spring P and core d is attracted, the spring I continuing the movement and maintaining the core d and plunger l5 completely raised, the circuit being then broken and the two cups no longer in electrical communication. The insulatingpartition prevents the forming of an arc, and the breaking of the circuit being effected, so to speak, in a closed vessel no alteration of the mercury can take place, it being possible to place the apparatus in an explosive medium and break the circuit without any risk of sparking.

lVhen the apparatus is raised, as shown in Fig. i, the elastic washer rabuts against the insulating-washerR and makes a tight joint. The apparatus might even be inverted without any of the mercury escaping.

The wire of the electromagnct is calculated so as to introduceinto the circuit onlya negligible resista-nce. In the case of alternating currents the metallic parts of the electromagnet would be suitably divided or laminated for diminishing induced currents, as is well understood. The current which leads to the mercury-cups may be so disposed as to be out of contact with the mercury when the plunger B is raised, as seen in Figs. 5 and 5, wherein the circuit-terminals are normally above the line 5* 5, which is the normal level of the mercury.

The action of the plungers is to first put the mercury in each cup in communication with its conductor and then the two cups with each other. inversely the breaking of the circuit is only produced between the two cups at the top edge of the partition c between two molecules of mercury and never between the mercury and the leading-in wires. The apparatus would be mounted upon a backing of insulatin g material.

When the apparatus is to be used for eurrcnts of high tension, the vessel A would be provided with one or more cups placed. intermediate of the two cxtreme compartments into which lead the conducting-wires, (see Fig. 0,) thereby producing two partitions. The breaking of the circuit is in this case produced at several partitions.

ln order to protect the leading-in wires from theaction of the mercurial vapors which disengage on the breaking of the circuit, and thus always preserve the perfect insulation et the terminals, the wires are protected by dipping curtains A', formed in one with vessel A, which project down below the lowest level of the mercury, thus :forming traps preventing the passage of the mercurial vapors ICO IIO

from the chamber when the breaking of the circuit takes place. Similar traps may be employed whatever may be the number of cavities in the vessel A. Two of these apparatus may be placed side by side, so as to constitute a bipolar circuit-breaker. (See Fig. 7.) In this arrangement the terminals are placed at different levels, so as to avoid the crossing of the wires supposed to be under casings. The two apparatus may be arranged so as to both break the circuit at one time by the action of a single electromaguet by providing on the cover M of the one apparatus a lug which abuts in rising against the teeth of a small fork mounted ou the cover M of the other apparatus, the play between the parts only permitting the apparatus to act mutually by the action oi' the spring I), so that the electromagnet will have no extra load to over come. The same arrangement would be em ployed for circuits of three or iive wires.

The apparatus maybe used both as a switch and as a circuit-breaker operated by hand, the cover M being raised by hand in the one case and automatically operated `in the other il the current exceeds the properlimit. VVithout the electromagnet it forms a simple switch, possessing the advantages before described when used as a circuit-breaker.

It will be evident that the apparatus may be used as a switch at a distance for various purposes, such as for tramway-contacts, rheostats, Sac., it being only necessary to insulate from the main circuit the circuit of the electromagnet and to control the latter from any point. The apparatus may also be used to limit the supply of current in a subscribers circuit, for example. In this case it is important that the apparatus be not tampered with by keepin g the plungers immersed when the electromagnet should act. Figs. S and 9 show a suitable arrangement, in which the cover M has instead of the iinger-piece a friction-roller 7s, on which acts a cam Z on a spindle m, connected to said spindle by a coiled spring o. The spindle is provided at one end with a handle p (see Fig. 9) and has a ratchet or other escapement for preventing its turning except in one direction. rlhe cam Z may be momentarily checked in its movement by a spring t. The entire device is inclosed in a case, leaving only the handle p exposed. Supposing the circuit to be broken, as shown in Fig. 8, in order to close the circuit the handle p is turned, the cam l being momentarily arrested by the spring not partaking in this movement. The coiled spring o is thus put in tension until it overcomes the resistance of spring t, whereupon the cam will be caused by the action of spring o to describe a complete revolution without its movement being prevented by the handle, the cam Z in rotating closing the cover M by means of roller 7c and closing the circuit. On the other hand, the circuit may easily be broken by raising cover M by means of the lever. In the case of a multiy.ple switch the cam Z would be arranged to act on several apparatus successively.

The apparatus may be used whatever may be the intensity and tension of the current, it being only necessary to proportion the dimensions of the layer of mercury above the partition to the intensity of the current and to increase the number or thickness of the ins ulating-partitions according to the voltage of the current.

I claim-V l. In an electric-circuit breaker or switch the combination of separate mercury-cham bers partitioned off from each other and capable of being put in electrical communica tion by the rise and union of the mercury on opposite sides of the partition, terminals communicating with the interior of the chambers at such a height therein as to be in electrical communication with the mercury only when the latter begins to rise above its normal level, and a mercury-displacing plunger for producing a rise and fall of the mercury, the rise of the mercury first making connection at the terminals of the chambers and afterward between the mercury in the two chambers and vice versa, so that the circuit will be made and'broken at at least three points and the insulating-partition will not be subjected to any electrical tension while the circuit remains broken.

2. In an electric-circuit breaker or switch the combination of separate mercury-chambers each containing mercury and partitioned olf from each other by insulation, the cham ybers however being capable of being putin electrical communication by the rise and union of the mercury which lies on the opposite sides of the partition, leading-in wires or terminals extending into the mercury-chambers and curtain A', dipping into the mercury in the chambers so as to trap oit the parts of the chambers containing the leading-in wires or terminals so that the terminals will be pro- IOO IIO

tected from any mercurial vapors which may r be produced in the chambers by the breaking of the circuit.

3. Inv an electric-circuit breaker or switch the combination of a series of-mercury-chambers containing mercury, with means for causing the mercury to rise in the chambers, adjacent mercury-chambers being separated by an insulating-partition and leading-in wires or conductors contained in the eXtreme or end chambers of the series whereby are formed a pair of mercury-chambers and an intervening mercury-chamberseparated from the end mercury-chambers by the partitions.

et. In an electrical-circuit breaker or switch the combination of circuit-terminals and an electromagnet for controlling` the action of the switch which the electromagnet comprises, a part D forming one cheek of the coil having an internal tubular polar extension gap, another cheek E having an internal polar eX- pansion e of decreasing` section, and a sheath C connecting parts D E.

In an electrical-circuit switch the combination of a plurality of inercury-chambers containing mercury and separated by an insulating-partition, a plunger adapted to dip into the mercury-chambers and to displace the said mercury and cause a union of the mercuryin the two chambers, an electromagnet for operating the said plunger, a cover and pivoted lever M in pivotal connection with the plun ger and provided with a snap-spring holding the said cover in one position and when sprung facilitating the movement of the plunger and pivoted cover.

G. In an electrical-circuit switch the combination of a plurality of mercury-cham bers conlraining mercury and Separated by an insulating-partition, a plunger adapted to dip into the mercury-chambers and to displace the said MAURICE BOUCHET.

Witnesses:

EDH/ARD l. MACLEAN, MAURICE HENRI PioNE'r, 

